Organic dyes containing dithieno[2,3-d:2′,3′-d′]thieno[3,2-b:3′,2′-b′]dipyrrole core for efficient dye-sensitized solar cells

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 3; no. 9; pp. 4865 - 4874
• Main Authors: Wang, Zhihui, Liang, Mao, Tan, Yulin, Ouyang, Liyan, Sun, Zhe, Xue, Song
• Format: Journal Article
• Language: English
• Published: 01.01.2015
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C4TA06705C

We report two new triarylamine-cyanoacrylic acid based push–pull dyes, X76 and X77 , featuring the π-conjugated linkers of dihexyl- and dihexyloxybenzene-substituted dithieno[2,3- d :2′,3′- d ′]thieno[3,2- b :3′,2′- b ′]dipyrrole (DTDP), respectively. The absorption, electrochemical, and photovoltaic properties for all sensitizers have been systematically investigated. Both dyes containing a DTDP moiety showed good light harvesting ability as compared to that of the reference dye incorporating the hexyl-substituted dithieno[3,2- b :2′,3′- d ]pyrrole (DTP) linker. Moreover, the substituents of DTDP moiety significantly influenced the electrochemical and photovoltaic properties of the dyes. The incident photon-to-current efficiency (IPCE) of the X77 -based device is higher at longer wavelengths, and extends to nearly 800 nm. A dye-sensitized solar cell employing the X77 photosensitizer and the Co-bpy electrolyte exhibits a power conversion efficiency of 6.6% measured under the 100 mW cm −2 simulated AM1.5 sunlight.